Regulation of DNA repair by ubiquitylation

The process of ubiquitylation is best known for its role in targeting proteins for degradation by the proteasome. However, recent studies of DNA-repair and DNA-damage-response pathways have significantly broadened the scope of the role of ubiquitylation to include non-proteolytic functions of ubiquitin. These pathways involve the monoubiquitylation of key DNA-repair proteins that have regulatory functions in homologous recombination and translesion DNA synthesis, and involve the polyubiquitylation of nucleotide-excision-repair proteins.